Some companies are selling illegal copies of VASP.
VASP can only be acquired legally in two ways:
All legal copies are centrally registered.
P4vasp 0.3.23 contains several improvements and bug fixes:
K. Z. Rushchanskii, S. Kamba, V. Goian, P. Vaněk, M. Savinov, J. Prokleška, D. Nuzhnyy, K. Knížek, F. Laufek, S. Eckel, S. K. Lamoreaux, A. O. Sushkov, M. Ležaić, and N. A. Spaldin